#help-10
1 messages · Page 342 of 1
What did you set it equal to?
Nah you're tripping, 3(3 + 15) = 54
what
um...
Ah hold on
Nah it's not 3 * 15 guys
you didn't manipulate that correctly
Yeah the issue here is you need to subtract by 54
0 = x^2 + 3x - 54
Then you shouldn't have x^2 + 3x + 54 = 0
So.. you're on the right track -
- What was your positive result?
- Why did you think your positive result was wrong?
6
it says it on the thing
I haven't seen anything except the original problem, without any problems worked out
oh
thanks
that was the issue
this is what it looks like
.close
Closed by @robust locust
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
help
Closed by @halcyon jewel
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
When a 3 digiit number is taken and reversed and this number is subtracted from the original number, and this number is then reversed again and added to the prev. number , u always get 1089. how do u prove ths?
there are exceptions but it works for most numbers
for example take 694
reversed: 496
difference: 198
reversed: 891
sum:1089
@twilit meteor Has your question been resolved?
this is a tough one, been thinking for a while
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
What was the final form of your equation before you found the variables k, h, and p
i found the same k and h, but a different p
@digital comet Has your question been resolved?
it does, thanks a lot!, so basically just put it into e and fraction forms, then L'H. Cool!
this, on roblox
Closed due to timeout
Use .reopen if this was a mistake.
.reopen
✅
What did u get for p
@digital comet Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I need help finding the explicit formula for a sequence
I'm working with this sequence, but I don't know how to begin finding the formula
I know that the negative signs are alternating, so there's likely a (-1)^(k-1)
My best guess is that the numerator should be 1, since its unchanging
I'm not really sure whats happening with the denominator
look at each term as two different terms (left and right)
I see that they seem to be counting up in alternating fashion
for example, the left part of the first term is 1/1, the second is 1/2, etc
1, 2, 3 ...
and
4, 5, 6 ...
I'm just not sure how to begin doing that
looks like a difference of 3, 2, 3, 2...
isnt the difference always 3
I don't see that
i see that from 1 to 1/4, the denominator changed by 3, then from 4 to 2, it changes by 2, and repeats
no no
the first term is 1 and 1/4 the second is 1/2 and 1/5
the third is 1/3 & 1/6
etc
oh i didnt notice the fact that two fractions are being subtracted within each term
so then the order would be (3/4), (3/10), (3/18), (3/28)...
you dont have to subtract them, just look at how the denominators always have a difference of 3 :)
yeah, within each term
i dont know how i could translate that information into a formula without subtracting them though
like for example i can rewrite the first term as (i'll call it $a_1$) $a_1 = \frac{1}{1} - \frac{1}{1+3}$
anonymemes
try to rewrite $a_2$
anonymemes
yes
and then making the negative sign alternate like this
actually thats not necessary
i just realized
it stays positive each term
yeah this is your full answer :)
Closed by @sturdy jasper
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how would you solve this?
if the event "only one converts his goal" happened, this could take place two ways:
Jack scores and Ben doesn't OR Ben scores and Jack doesn't. how would you calculate the probabilities of these two using the info given in 1st sentence?
0.3x0.6 + 0.7x0.4
what values do u sub in for P(A|B)=P(AB)/P(B) ?
so the probability of one happening is 0.18 and the other 0.28, but we know this event occurred (one hit the ball) so the probability of it being Ben, (the 60% guy) would be simply: 0.18/(0.18+0.28)
@jagged hawk Has your question been resolved?
Closed by @jagged hawk
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
can someone please help me with this question?
Closed by @hard citrus
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
no
what are you doing with the
6^(36x)
none if it seems valid
Do i take the natural log of the whole thing then?
do u know this rule
So
According to that rule
Is it just
Sorry guys i cant believe i cant solve it
Im taking upper core mechanical engineering (dynamics) classes and i find it weird that i dont use as much calculus for it
not quite,
you'd also need to multiply by derivative of 36x because chain rule
@primal idol Has your question been resolved?
Im having a hard time
Understanding it
And ive taken Advanced Engineering Math
Sorry
How many nests do you have?
Nests?
One function, nested in another function, nested in another function, etc.
your goal is to find the derivative of each "level" on its own, in series (in a chain.. hence, the chain rule)
d/dx f(g(h(x))) =
Yeah
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hey i am stuck what do I do next
if 3 is ur remainder
U would just write it as 3/x-1
why
soz i don’t know a lot about long division
so for any remainder we have to divide it by the whole like thing
ah okay
Math
Closed by @rose ferry
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hello! I need some university-lvl help
I need to find the lateral surface area (I dont even know if I am using the right terms lol) of my eye's cornea that gets in contact with my soft contact lens. I found that the cornea is a prolate spheroid so I guess I can divide it to 2 to find it but I dont know if I should start by finding lateral surface area of the prolate spheroid. I hope you got what I am trying to say
Any help is appreciated!!
@coarse compass Has your question been resolved?
.close
Closed by @coarse compass
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hi, im struggling to understand how distributive law was used here, i jsut cant seem to visualize how it was done. can anyone help D:
@cloud stream Has your question been resolved?
@cloud stream Has your question been resolved?
.close
Closed by @cloud stream
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
if x^3 + px + q has a double root, show that the double root must be -3q/2p, where p cant be 0
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
2
What have you tried so far?
Doesn't double root mean 2 roots that are the same?
yes
and i subbed
-3q/p into it but the equation is coming out too messy
so i dont think i should do that
That would be the root of P'(x), not p(x) though
If u sub the value of x you got then those will be points of maxima/minima
Well yeah, while you might be able to solve it that way
Might not be ideal
Notice that P'(x) is def simpler
The double root is both root of P(x) and P'(x)
Wait so it doesn't mean that P(x) has two roots which are same?
Mb then
i alr made x^3 + px + q = 3x^2 + p
It's an obvious consequence of being a double root.
Hmm, wouldn't that be dead end as well
yeah
I guess so
Assume the roots to be a,a and b then ig
still confusing 😭
Are u sure u copied correctly the question?
Ah right. That is def a possibility
that makes more sense
when i did this problem i got -3q/2p as the root
Ahh
anyway i think viete's relations provides fairly simple way of solvingthis
Its ok
is that the
.
Hm, is that way simpler.
loll
Ye
ye
Ye
ight
ill try
should i sub the -3q/2p as a root
like
am i allowed to do that
if i have to show
Np
Closed by @grizzled tinsel
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
The diagram shows the curve y=x^3 - x +3 and the point P(-2,-3) on the curve. The line L cuts the curve at P, and is tangent to the curve at another point A on the curve. Find the equation of the line L
ignore the random bit below the graph they misplaced it on the wrong question (thats working out from it)
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
How did you start off?
Given in point P
What's the derivative?
y' = 3x^2 -1
What should that equal to
that?
nots ure what to sub for x
just coz the point P
isnt the other intersection
that would give it
do i like
leave (3x^2-1) as a variable
as the gradient
then point gradient with -2,-3
set the tangent point as (t,f(t))
L = f'(t)(x-t) + f(t)
put (-2,-3) in it
an solve
ill try
You might get a cubic but you can use rrt in this case
wahts rrt
Rational root theorem
never heard of it
ye
but then it comes out as
oh
hol don
but hten it comes out as lke
-3 = f'(t)(-2-t) + f(t)
solve for t
ye
Yes
No
Since it's f'(t), replace x with t
Note that we assumed t to be the x coordinate of the point we wanna find
Yeah
ok
3t²-1
right
so
x = -2 and 1
do i find the gradient from here
coz
1 is my x coord for the other point
Right
Yeah
You can coz you have the x coordinate
How did u solve it then
I thought you never heard or rrt
Damn
If you're allowed a calculator then, idk
But if not then yes, sometimes
Sure
Closed by @grizzled tinsel
Use .reopen if this was a mistake.
That one u solve factoring it
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hello, I need help understanding the dimensionality and reason for applying a transpose on lambda
this problem refers to the sensitivity of an adjoint system
in the following:
dj/dtheta has dimensions 1xP. dJ/dx has 1xN, df/dx is NxN and df/dtheta is NxP dimensional
so multiplying dJ/dx with (df/dx)^-1 yeilds a 1xN martix which can be multiplied with NxP to give 1xP which satisfies the equation
but taking the transpose of lambda gives dimensions Nx1 which cannot be multiplied with 1xP
lambda_T is defined as: -dJ/dx * (df/dx)^-1
<@&286206848099549185>
yep
my question is why do we transpose lambda
it changes the dimensionality meaning we cant multiply
which grade
what?
wdym grade?
from which country??
the topic is adjoint sensitivty
gradient based optimisation
<@&286206848099549185>
@dusky marten Has your question been resolved?
<@&286206848099549185>
I will beat u up
bro open a new help channel
im using this one
read #❓how-to-get-help
<@&268886789983436800>
<@&286206848099549185> can some explain this please?
can someone explain to me why in adjoint sensitivity, we define lamdba_transpose instead of just lambda? i dont understand how the dimensions work? <@&286206848099549185>
@dusky marten Has your question been resolved?
@dusky marten Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Consider two solid spherical balls, one centered at $\left( 0, 0, \frac{21}{2} \right),$ with radius $6$, and the other centered at $(0,0,1)$ with radius $\frac{9}{2}.$ How many points $(x,y,z)$ with only integer coordinates are there in the intersection of the balls?
Dork9399
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
I'm on step 2
I can visualize the two objects, but I don't know how to find the number of lattice points inside the intersection.
@honest forum Has your question been resolved?
<@&286206848099549185>
@honest forum you can find the intersection of the two balls as a disc. Then once you have that disc, which is constrained to a plane z = a for some number a. If a is an integer, you just count the lattice points on that disc as if it were centered at the origin. If a is not an integer, then you have 0.
Wouldn't the intersection be an object, not a disc?
what is the definition of object?
Closed by @honest forum
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
My question is if there is any site or place where i can learn about union set. And where it doesn't cost money cuz i am poor 🙂
union set?
Meant to say 'set union' I guess
no i meant lik
like your profile picture
This math video tutorial provides a basic introduction into the intersection of sets and union of sets as it relates to venn diagrams.
Translating Words to Algebraic Expressions: https://www.youtube.com/watch?v=QEnFIgN8UBw
Words to Equations - More Problems:
https://www.youtube.com/watch?v=VjPX-XlN7Ok
Consecutive Integers ...
thank you very much
thx, i like to use that
.close
Closed by @dense vale
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
A journal article reports that a sample of size $n=5$ was used as a basis for calculating a 95% confidence interval for the true mean natural frequency (Hz) of delaminated beams of a certain type. The resulting confidence interval was $(229.764, 233.504)$. You decide that a confidence level of $99%$ is more appropriate than the $95%$ level used. What are the limits of the $99%$ interval? Assume that the data collected follows a Normal distribution.
cookie2
@cosmic veldt Has your question been resolved?
<@&286206848099549185>
@cosmic veldt Has your question been resolved?
@cosmic veldt Has your question been resolved?
Closed by @cosmic veldt
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Why do I get Sin (35) * 3 different from Sin (65) * 2 here?
does this triangle exsist?
fine
no
Wait what?
Oh wait
Thats because when you have 3 given sides, then there's a unique solution for the three angles right?
yes
That makes sense cause I made up the sides and the angles
Closed by @real kelp
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
funnily #help-7|zen1thxyz has the same problem
I would help you , but im very dumb. Sorry.
what?
.-.
.close
Closed by @upbeat plinth
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how do i do 10b
<@&286206848099549185>
<@&286206848099549185>
!15mins
Please only use the <@&286206848099549185> ping once if your question has not been answered for 15 minutes. Please do not ping or DM individual users about your question.
@spark horizon Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How do I show that S5 is generated by the set {(12)(23)(34)(45)}?
is there a typo in the problem...?
where are the commas in the set
should there be commas separating the transpositions
sully
s5 is cyclic trust
i do not trust you
damn
Wait im also confused too
anyway yeah those are probably 4 elements?
r there supposed to b e commas lol
yes
then it is poorly posed
I think then let's just say there's commas
then what?
i know that this thing is a theorem
but idk how to shuow it

by theorem obviously
no intuition
Like "every sN can be written as a product of transpotition"
i think
yes great
n-1 transpositions*
so S_5 is generated by its transpositions
so you could just show you can make any transposition from these 4
u mean like 13, 14, 15, 23, 24, 25, 34, 35, 45?
cyclic permutations 👀
maybe the set is also permuted in some manner
and you want to prove that symmetric group under 5 is generated by the other permuted set.

like the transpositions are permuted as well

huh
@cosmic veldt Has your question been resolved?
yeah i think it’s a set of five different transpositions
lol
it’s basically saying “bubble sort terminates”
yea that works as well
to prove this just use an algorithm (bubble sort) to get any element of S5
..
yes i think so
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how can i find the exact value of cosec (-60)
cosec(x) is an odd function
so cosex(-x) = -cosec(x)
yep
so it would be -1/sin(60)?
yes
and then i use exact values for sin60
yup
Closed by @hoary kindle
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How do I factor when a doesn’t equal one
um, idk, you let the penguin eat the 1?🐧
Ohhhhhh I get it now
I don’t really know how to give context…… Like my pre algebra class has been factoring variables and numbers and now we are gonna do things like positive c, negative c, and when a doesn’t equal one.
But I don’t really know what that means because when we are factoring it’s not like we are trying to figure out what the variable is anyways, so why do we need to learn cases when a doesn’t equal one
yeah so there's multiple ways you can go about this
the most common method is to split the linear term
are you asking how to factor quadratics in the form
[ ax^2 + bx + c ]
where $a\ne 1$...? you should tell us what you mean, we don't know what `$a$' is automatically
cloud
non monic?
I think
I can just ask my teacher on Monday
My quiz is on Thursday so I got time
.close
Closed by @fresh lotus
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
does anybody know where i went wrong
This image is illegible
darn i wanted to make a joke about how it was just legible enough for me to make out that it says final exam at the top
but it also says 2023
hm haven't seen the definition of centroid, is it the point for which the integral w.r.t. to x & are equal on both sides?
yeah makes the most sense to me
well x is fixed due to symmetry
and I presume you determined y by setting the two integrals w.r.t y equal?
or have you been given a specific other formula for centroid coordintaes @dry creek
hm I don't want to write a proof for it, but I presume that definition is synonymous to the integrals being equal in x & y
wdym being equal in x and y exactly?
for an arbitrary shape
our prof didnt really go over too much what it really means
but i do know the formula is guarenteed to work
but centroid is just weight center right
so it makes sense for the integrals to be equal
with respect to any orthogonal basis
it'd be the same in 3D
or 4D
we havent learned orthogonal stuff lol he just gave us the formula
kk, but it's clear that xdash = 0 right
uh
oh its asking for y coord here
yea but I mean it's clear why xdash = 0 right
ok
well because the shape is symmetrical
y = sqrt(4-x²) is symmetrical to the y-axis
and y = 1 as well
ok
thereby the enclosed shape is symmetrical as well
and the centroid must lie on the y-axis
now, if you imagine the centroid as "weight center"
it also makes sense that ydash must be in between here:
on this red line
ok
since the weight center of that half disk must lie on the disk
imagine balancing that shape on one finger
if you want to stay it on your finger, then you need to place it somewhere on that red line
otherwise it'll tip over
nywys back to the task lol
ok so how far did you get in evaluating ydash
with the formula you provided:
i evaluated it fully but its wrong
hm k do you happen to have the solution
I'd just like to briefly check whether my former thesis is true
k I'll check your steps now
where is your final value for the area?
its -6pi/3-sin(8pi/3)-3sqrt3/2
but that's negative
i made it from -sqrt3 to sqrt3 along the x axis instead of y
yea works as well
which is harder but should still work
hm the substitution for theta seems right but I'm not sure what for
because i didnt know what to do with the sqrt
but you can just evaluate it
directly
without a calculator
how would i do the sqrt part without trig sub?
hm I may have done expansion (if they want the solution just as estimate rather than exact value
but exact value trig sub yeah k
yeah they want exact value
me too lol
the fact that i got sin(8pi/3) which i dont think is a value of the unit circle is werid since usually these weird values dont show up for these problems
and the negative area lol
oh ok
I think it has to do with the periodic nature of sin/cos?
that you can switch with - & 2pi in some places and get the right value
but I'm not sure where that flaw occurs
yeah the answer key just like directly solves for it
wait why is it - - here
ah nvm
yeah getting 4pi/3-sqrt(3) here shall be the intended
don't see it sry
wait do you mean the answer should be 4pi/3 - sqrt3?
oh yeah
good luck with finding it, gtg in a sec
alr
@dry creek Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How should I start with this?
kinda stuck on what to do.
what are the conditions an ideal must satisfy?
show that the intersection satisfies those conditions
my sir can probably help you with this @fathom flicker
he has a doubt about ideals
@fathom flicker
Let me ask my sir @gilded needle .. I have a doubt about what a "left" ideal is
is it such that for all i in I, that for all a in R,
ai in I
yes
your ring is non-commutative
it is not necessarily the same that ri=ir
does this clear your doubt?
if i were to solve it, i would use A⋂B?
wdym
the intersection of arbitrarily many left ideals is surely a left ideal, if my sir is not very mistaken
Let A and B be ideals of R. Then ∃ 0 ∈ R such that 0 ∈ A and 0 ∈ B. Thus 0 ∈ A ⋂ B. Hence A⋂B is nonempty.
something like that?
you dont need a quantifier
or do i specify that A and B are left ideals...
just 0 is in R, so 0 is in A and B
you should do this as well
so something like this?:
Let A and B be left ideals of R. Then 0 ∈ A and 0 ∈ B. Thus 0 ∈ A ⋂ B. Hence A⋂B is nonempty.
yes, you might want to mention why 0 is in A and B, but otherwise is fine
next you'd show that A n B is closed under addition
and that it is closed under additive inverses, and finally under left multiplication from R
Let x,y ∈ A⋂B. ... here's where I'm kinda stuck
well if x,y are in A n B
then they are in A
what do you know about x + y, if x,y are in A
it is also in B?
no
well yes, but that isn't what i was asking about
you have x,y in AnB
that means that x,y are in A
look at the second condition for an ideal
so x+y in AnB?
how did you get to that
Let x,y be elements of AnB such that x+y are in A and in B. thus x+y is in AnB? not sure... i just went in directly
follow along with me, and answer the questions i ask
let x,y be in A
assuming A is a left ideal of R
is x + y in A?
yes.
since it is an ideal of R
ok yes
it is the second condition
so you would word your proof as
let x,y be in AnB.
- then x,y are in A, so x + y is in A
- then x,y are in B, so x + y is in B
so x + y is in A and B
so x + y is in AnB
its a much clearer version of this
i see it now
Let x,y in AnB. Then x,y in A and x,y in B. thus there exist -x,-y in A and -x,-y in B?
note that you don't need both x and y now
you can just let x be in AnB
otherwise it looks fine
Let x in AnB. Then x in A and x in B. thus there exist -x in A and -x, in B. We have x+(-x) = 0 in AnB
yeah looks fine
Let x,y in AnB such that xy in AnB. Let z in AnB such that z(xy). Thus, z(xy) = (zx)y in AnB.
Is this good enough?
no
you are trying to show that if x in AnB, and r in R, then rx is in AnB
start by letting x be in AnB and r in R
oh my bad...
since x in A, ra in A, and since x in B, ...
np
it is very similar to the other ones we did
you just break it down to the case in A and B, and show that ra is in A and B, and so in AnB
Let x,y in AnB, then x,y in A implies that xy in A and x,y in B implies that xy in B.
right?
Let x,y in AnB and r in R. Then x in A implies that rx in A and x in B implies that rx in B.
Let x in AnB and r in R. Then x in A implies that rx in A and x in B implies that rx in B. Thus rx in AnB.
Since A and B are noncommutative, then AnB is a left ideal of R
Since A and B are noncommutative, then AnB is a left ideal of R
this doesnt really make sense and i would drop it
i would just say that AnB satisfies all conditions to be a left ideal
its kinda the conclusion
okay^2
thank you so much
.close
Closed by @open kelp
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
can someone explain the difference in approaches for part c of each question, why did we treat X as exact same for one but not for other?
I don't understand what you are asking
@strong forum Has your question been resolved?
For 1C on the first very first image, the solution is Var(V)=4Var(Y) + 4Var(U) instead of using V=10X-8
There is nothing particular about either problem that makes one approach more special than the other. That one is missing the justification that Cov(Y,U) = 0.
if I try doing
V=10X-8
I get Var(V) = 10^2 * 16
which isn't 832
Like I already said, "That one is missing the justification that Cov(Y,U) = 0."
what does Cov(Y,U) mean sorry?
that they are independent?
The covariance of Y and U
Closed by @strong forum
Use .reopen if this was a mistake.
.reopen
✅
Sorry just one more thing, why do both methods not result in the same answer?
If independent we do that method if not we do the one I suggested?
I said nothing about independence. If the answers aren't correct it's probably because they did the calculation wrong and assumed Cov(Y,U) = 0 when it's not.
you should do the calculation yourself as a matter of practice
so value of covariance effects whether you use Var(10X-8) or 4Var(Y)+4Var(U) using the Var(aX+bY)=a^2Var(X) + b^2Var(Y) property?
because I did the calculations and both of those methods lead to different answers
I also never heard of covariance before and assumed cov(y,u)=0 meant y and u are independent since thats when var(aX+bY) thing works
at least i was taught
No, the property is Var(aX+bY) = a^2 Var(X) + b^2Var(Y) +2abCov(X,Y). They omitted that term, so it is either zero or they are wrong.
zero covariance does not mean independence
@strong forum Has your question been resolved?
Closed by @strong forum
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how do I solve this?
express tan4x in terms of sine and cosine
should i use tan(2θ-2θ) or smth?
maybe tan [2(2θ)]
or tan4θ=(sin4θ)/(cos4θ)
lemme try
there is
square the first equation
yea
yes there is
where did that come from bro?
oh wait you sqaured both sides
ye
yeah but what do I do with that?
@silk monolith Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
firstly
u' is not 12x cos x
it needs to be simplified further
u = fg
f = 6x^2
g = sin x
use product rule
@pine badger Has your question been resolved?
Like this?
<@&286206848099549185>
@pine badger Has your question been resolved?
@pine badger Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hi, I'm trying to minimize/simplify a boolean expression I got from a karnaugh map to see if i can reduce it any further.
This is my working so far and I can't tell if im just stuck or it can't be simplified further.
<@&286206848099549185>
@haughty comet Has your question been resolved?
@haughty comet Has your question been resolved?
@haughty comet Has your question been resolved?
.close
Closed by @haughty comet
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
!filetype
Please post images (such as PNGs or JPGs) of the question rather than other filetypes such as PDFs which have to be downloaded. Non-image downloads can potentially contain viruses or other security risks.
.close
Closed by @hot heart
Use .reopen if this was a mistake.
@timid silo in the future, please do not hop around to other channels and advertise your current one or interrupt what's happening over there
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
maybe they want you to fully simplify
I don't really understand what it would entail to "fully simplify" here
square the 5tan(theta)
?
r u familiar with trignometric pythagorean identity
a^2+b^2?
(sinx)^2 + (cosx)^2 = 1
yeah that I know
I'm sorry I don't understand
both sides of what
of this equation
something seems very incorrect here
ah wait 1 sec
but that's just this identity
mmmm
I see what you mean
make it just sec
but its not tan^2
I mean 5sec(theta)
is all that comes to mind
because 25+25tan^(theta)
take the 5 out
ok I got it
.close
Closed by @worldly lagoon
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
what can i cancel out in this equation. im confused by the plus sign in the numerator
n(n + 2) + (n + 1) / (n + 1 )(n +2)
hello
hello
dp
yea thats right